1. Field of the Invention
This invention relates to a sign made of a composite material by a pultrusion process.
2. Discussion of the Prior Art
Composite materials are well known for making many different types of items. A composite typically comprises a reinforcing component, which may be in the form of fibrous strands or woven or non-woven sheet, encapsulated in a resinous binder. Typical applications of composites are boats, automobile body parts, springs, beams, conduit, fishing rods, tennis rackets, and skis. Many different types of resins have been used in making composites including thermosetting resins, thermoplastics and elastomer resins. Many different types of fibrous materials have also been used including glass, aramid, carbon, thermoplastic fibers and hybrid fibers.
Composite signs have also been made. Processes for making composite signs include compression molding and pultrusion. In compression molding, the layers of the sign, including a sign panel layer with the sign identification matter on it, are laid up in a mold and the mold is filled with a resin under pressure which encapsulates the layers when it sets up.
Pultrusion has been used for producing products of a constant cross-sectional area in a continuous process. One or more longitudinally continuous fibrous components of the product are pulled through a resin bath just prior to being pulled through a forming die in which the resin cures and the product takes on the desired cross-sectional shape. When the cured product exits the die, it is cut off to provide the desired length of the product.
Pultruded products bearing legends have been made by printing a surface layer prior to pulling it into the die, or by printing on, or affixing a sign panel to, the exterior of the product. However, the surface layer in pultrusion is usually an open, non-woven material which does not provide a good printing surface, particularly for small characters or detailed graphics. When the surface layer is molded as part of the pultrusion, legibility and definition of a legend printed on the layer has been a problem. Also, the diameter of a print wheel for printing the surface layer is impractical for long products or where the print length is short but the print repeat length is long. Printing or attaching a sign panel on the surface of the pultrusion subjects the identification matter to damage such as weathering and scratching.